<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .item_ul {
      width: 500px;
      height: 800px;
      float: left;
    }

    .item_li {
      width: 250px;
      height: 400px;
      background-color: aqua;
    }

    .item_ul2 {
      float: left;
      width: 250px;
      height: 400px;

    }

    .item_li2 {
      width: 125px;
      height: 100px;
      background-color: brown;
    }
  </style>
</head>

<body>
  <div class="item">
    <ul class="item_ul">
      <li class="item_li">1</li>
    </ul>
  </div>
</body>

</html>